The present invention relates to a new and improved flashlight and more specifically to a flashlight which may use a semiconductor diode as a source of light and/or may have a touch-sensitive switch apparatus. It has been suggested that a flashlight may use either a red or green light emitting diode in place of a conventional bulb. When a mechanical switch is actuated, the light emitting diode is energized by a battery in the flashlight. A flashlight having this construction is disclosed in U.S. Pat. No. 4,290,095.
It has previously been suggested that a flashlight could have springs which drive a generator to provide power. The output from the generator is used to energize a conventional light bulb. A flashlight having this construction is disclosed in U.S. Pat. No. 3,099,402.
A flashlight having a light emitting diode which periodically flashes to aid in finding the flashlight in the dark is disclosed in U.S. Pat. No. 4,228,484. The flashlight disclosed in this patent has a battery which energizes a conventional light bulb when a mechanical switch is actuated. The light emitting diode continuously flashes when a battery is disposed in the flashlight.
It has previously been suggested that a touch sensitive switch could be used in association with a wristwatch. A wristwatch having a touch sensitive switch is disclosed in U.S. Pat. No. 4,063,111.
The present invention provides a new and improved flashlight, that is, a source of illumination which is movable by the person operating the flashlight. The flashlight includes a light source. The light source may be a semiconductor diode which is capable of emitting light when energized. Electrical circuitry interconnects the diode and a source of power which may be a battery or a generator.
One embodiment of the electrical circuitry is associated with a switch which is operable between a first condition and a second condition. When the switch is in the first condition, the light source is energized to provide light of a low intensity to facilitate locating the flashlight. When the switch is in the second condition, the diode is energized to provide light of a high intensity which may be sufficient to illuminate objects spaced more than six feet from the flashlight. The light source may be a diode which emits white light when energized.
The electrical circuitry may be associated with a manually movable switch member. Upon actuation of the manually movable member, a transistor or other semiconductor device is switched between conducting and nonconducting states. The light source, which may be a white light emitting diode, is changed between a condition in which it is energized to emit high intensity light and low intensity light in response to actuation of the transistor between the conducting and nonconducting states.
A regulator may advantageously be connected with the light source and the source of power to maintain the intensity of the light emitted from the diode or other light source substantially constant. When the diode or other light source is energized to provide high intensity light, the regulator is effective to maintain the intensity of the light constant even though the strength of the source of power connected with the diode decreases. This enables light of a uniform intensity to be obtained from the light emitting diode even though a power source which gradually discharges with the passage of time is used to energize the light emitting diode.
The flashlight may have a touch sensitive switch. The electrical circuitry connected with the power source and the light source is operable in response to the touch sensitive switch being touched by the person operating the flashlight. The touch sensitive switch may have terminals which are engagable by a portion of a body of the person operating the flashlight to enable electrical energy to be conducted between the terminals through the body of the person operating the flashlight. A plurality of touch sensitive switches may be provided to increase and decrease intensity of light emitted from the light source. The light source may be energized to provide continuous or intermittent illumination.
There are a plurality of inventive features and embodiments of the invention disclosed herein. The inventive features may be used together or separately. The features of one embodiment of the invention may be used with features of another embodiment of the invention.